FLORENCE, Italy, March 6 (Reuters) - African immigrants and Italians protested in Florence for a second day on Tuesday, chanting "no more racism" and criticising the anti-immigrant League party for stoking racial tensions after an Italian man shot dead a Senegalese street vendor.

Police said Roberto Pirrone on Monday fired six pistol shots at close range, killing Idy Dienec as he sold leather bags, umbrellas and trinkets on a bridge in the Tuscan city, one of Italy's most popular tourist destinations.

Later, dozens of immigrants marched through the historic centre of Florence, knocking over trash bins, motor scooters and large flower pots.

On Tuesday, some 500 African immigrants and Italians staged another protest on the bridge where the shooting took place.

Tensions ran high as 100 people approached riot police wielding shields and batons, but there were no clashes. Florence Mayor Dario Nardella told protesters to remain calm, as did senior members of Florence's large Senegalese community.

The shooting came a day after a parliamentary election in which politicians, especially the anti-immigrant League, often portrayed migrants as criminals and called for mass deportations.

Police told Reuters on Tuesday the murder was not racially motivated, citing testimony Pirrone gave to investigators after his arrest. Pirrone, who had a license to carry a weapon for sport, was suicidal and lashed out in a state of confusion, investigators said.

FIRST BLACK SENATOR

But the timing of the attack has raised suspicions among Florence's Senegalese community.

In the election, the League became the second-biggest party in parliament.

"The fact that the elections went the way they did shows the kind of mood the country is in," said Pape Diaw, a representative of the Senegalese community. "Italy has become a country where blacks are shot on the street."

Last month a man with neo-Nazi sympathies and ties to the League opened fire on African migrants in the city of Macerata, wounding six before he was captured.

Claudio Borghi, the League's economics chief, said on Tuesday his was not a racist party, citing the election of Toni Iwobi, a Nigerian immigrant, as a senator on Sunday.

"I'd like to point out that the first black senator in the history of the Italian republic is one of ours," Borghi told Reuters. Iwobi, the party's spokesman on immigration, has been a League member for 25 years.

Dienec, the 54-year-old victim of Monday's attack, had legally lived in Italy for many years, police said.

More than 600,000 boat migrants have arrived on Italian shores in the past four years, making immigration a top concern for voters during the campaign.

The League and the 5-Star Movement, which emerged as the largest party in the vote, both have promised to ramp up deportations of irregular migrants.

Monday's shooting is not the first targeting African vendors in Florence. Six years ago, an Italian right-wing extremist shot dead two street sellers and wounded three others in a racist rampage.